Noiseless lock unit



E. L. SCHLAGE NOISELESS LOCK UNIT Jan. 20, 1959 'Filed Oct. 22'. 1956INVENTOR. ERNEST L. SCHLAGE 7 M v ATTORNEYS United States i NOISELESSLOCK UNIT Ernest L. Schlage, Burlingame, Califi, assignor to SchlageLock Company, a corporation Application October 22, 1956, Serial No.617,456

4 Claims. (Cl. 292-341.12)

IQC

Fig. 4 is a vertical cross section taken along lines 4-4 of Fig. 3;

Fig. 5 is a front elevation of a strike showing another modification ofthe invention installed in the strike box; and

Fig. 6 is a horizontal cross section as taken along lines 6-6 of Fig. 5.

In detail, and with reference to Figs. 1, 2 the invention is shown incombination with a latch set generally designated 1 installed in a door2 and adapted to cooperate with a strike 3 on the door jamb 4.

Although the present invention lends itself to use with various types oflatches and locksets a simple ,form of latch is shown in Fig. 1 having alatch bolt 5 which is spring urged to the projected position shown by aspring 6.

The latch bolt 5 is bevelled as at 7 to provide a camming action betweensaid bolt and the flared strike lip 8 on the strike 3 as the door isclosed. Such camming action causes the latch bolt 5 to be retractedinwardly into its housing 9 against the urgency of spring 6duragainst-the strike plate on the door jamb during closing movement ofthe door, the noisy action of most doors results from the latch boltstriking a stop as it is disengaged from the strike plate and projectedinto the strike box. Although the stop for the latch bolt usuallycomprises a projection integral with the bolt which engages the faceplate of the lock unit, it may be carried by the latch bar to which thebolt is secured. In any event the relatively loud noise attending thedoor closing results from the impact caused by metal to metal contact asthe outward travel of the latch bolt under the urgency of the latch boltspring is suddenly arrested.

It hasbeen suggested,'in the past, that such noise may be eliminated byproviding a cushioning material between the latch bolt and the stop, butthis procedure requires modification, or at least disassembly, of thelockset.

It has also been suggested that means be provided in the keeper openingfor absorbing the impact of the projecting latch bolt. However, suchprior art devices have involved intricate and expensive shock absorbingdevices and have been considered impractical in the trade for thisreason. See, for example in this connection Hurd 1,005,841, Voight1,004,716 and Voight 1,003,219.

It is therefore the main object of this invention to overcome thedisadvantages of prior art devices for silencing latch bolts. l

Another object of the invention is the provision of a device forsilencing a door latch unit that is relatively inexpensive to make andinstall.

Still another object of the invention is the provision of a noiselesslatch unit that does not require modification of the latch unit itselfbut which may be conveniently installed in the strike box.

Yet another object of the invention is the provision of a noiselesslatch unit that is readily accessible for adjustment and does notinvolve the use of any tools in addition to a screwdriver to performsuch adjustment.

Other objects and advantages will be apparent from the attached drawingsand from the following specification.

Fig. 1 is a horizontal cross section through a latch unit and itsassociated door and jamb showing the preferred form of the invention;

Fig. 2 is a perspective of the strike and the strike box with portionsbroken away and in section to show in'- ternal structure;

Fig. 3 is a front elevation of a strike showing a modified form of theinvention installed in the strike box;

ing said closing movement.

The strike 3 is provided with a generally rectangular aperture or keeperopening 11 which is adapted to receive the outer portion of bolt 5 whenthe door is completely closed. The door jamb 4 is provided with arecessor mortise 12 in registration with the opening 11 and into whichthe bolt 5 projects.

Although not required in all instances, it is preferable to provide astrike box generally designated 14 within the mortise 12 (Fig. l). Thestrike box 14 includes a bottom plate 16, sidewalls 17 and peripheraloutwardly extending flanges 18. The strike plate 3 is provided with apair of countersunk screw holes 19 (Fig. 2) for receiving therein thewoodscrews (not shown) that secure the strike 3 to the jamb 4. Theflanges 18 of the strike box may be correspondingly apertured to receivesaid screws so that the strike box 14 and strike 3 may be firmly securedto the jamb 4 at the same time.

' Although the particular means for limiting the outward movement oflatch bolt 5 may take various forms, in Fig. 1 such means is shown as anoutwardly'extending projection 19 on the latchbolt 5 that is adapted toengage the inner side of the faceplate 20 of the latchset 1. It will beunderstood that the faceplate 20 is provided with an opening 21generally complementary to the crosssectional contour of the outerportion of the latch bolt 5, except for the projection 19, so that thebolt is reciprocable within said opening. As noted above, the impact ofthe stop 19 (or any other portion of the latch bolt) engaging thefaceplate 20 creates considerable noise unless some means is providedfor cushioning such impact.

By the present invention the outward movement of the latchbolt 5 isarrested by a cushion 23 preferably of relatively loosely packed fibrousmaterial such as felt. Obviously other materials having impact absorbingqualities such as soft rubber may be employed if desired.

In the structure of Figs. l, 2 the cushion 23 is generally rectangularin form and is supported on a plate 24 and secured thereto as by glue orin any other convenient manner. The bottom plate 16 of strike box 14 isprovided with a threaded aperture 25 for receiving therein the shank ofa screw 26. Plate 24 is apertured as at 28 to loosely receive the, shankof screw 26 therethrough and the cushion 23 is provided with an aperture29 for 1 By the above, described structure it is seen that the cushion23 may be adjustably positioned until it engages the bolt 5 and stopsfurther outward movement of the latter just before the stop 19 on latchbolt 5 engages the faceplate 2%. In other words, the latch bolt 5 iscornpletely brought to rest by the cushion 23 so that no noisewhatsoever results.

it will be understood that the cushion 23 should be positioned as farinto the strike box 14 'as is possible and still cushion the impact ofthe bolt. If, aite'r a period of time, the cushion 23 loses some of itsresiliency and becomes compressed so as to permit the latchbolt stop 19to engage the faceplate 20, it is a simple matter to back out theadjusting screw 26 with a screwdriver until the desired cushioningeffect is achieved.

A modified form of the invention is shown in Figs. 3, 4 wherein agenerally rectangular cushion 33 is mounted on a plate 3 positioned asbefore Within a strike box 35.

in this instance the bottom 36 of the strike box 35 is provided with apair of upper and lower threaded apertures for receiving a pair ofscrews 38. In this case the screws 33 are provided with fianges 39spaced from the heads of the screws to provide annular grooves intowhich U-shaped slots 411 in plate 34 are received. By this structure itis seen that no spring is required and the plate 34 and cushion 33 maybe adjustably moved by turning screws 33 until the cushion is properlypositioned as explained above.

Still another modification is shown in Figs. 5, 6 wherein a hinged platedd is provided for supporting cushion 43. This plate 44 may be securedby means of a hinge 45 to one sidewall 46 of the strike box 47 and ascrew 45 provided as in Fig. l cooperating with the bottom 50 of thestrike box 47 and the plate 44. In this instance a flat spring 49 isinterposed between bottom 5% and the plate 4 5 to urge the plate andcushion toward the latchbolt 5.

It will be noted in Fig. 6 that the hinge 45 should be positioned on theside of the bolt 5 opposite the leading edge so that the plate may beswung a considerable amount to the dot-dash position shown withoutinterference with the latch bolt except at said leading edge.

It will be apparent that the present invention provides an extremelysimple means for silencing a latchbolt that is inexpensive to installand which may be readily a justed to compensate for wear withoutrequiring the lockset to be disassembled or modified.

The very specific embodiments above described should not be taken asrestrictive of the invention since it is obvious that minor variationsin design may be resorted to without departing from the spirit of theinvention or from the structure defined in the following claims.

I claim:

1. For use with a door latch unit including a latch bolt, a springurging said bolt to projected position, and opposed shoulder means forlimiting the extent of projection of said latch bolt, the combinationof: a strike adapted to be engaged by said latch bolt for retractingsaid bolt upon closing movement of such door, said strike being providedwith an opening adapted to receive said bolt therethrough when such dooris closed, a strike box in registration with said opening for receivingsaid bolt therein, a plate positioned in said box, means mounting saidplate below the level of said opening for limited adjustable movementtoward and away from said opening, and a stop of yieldable cushionmaterial carried by said plate and adapted to be engaged by said boltwhen the latter is projected to substantially its full extent for'noiselessl'y absorbing the impact of said shoulder means.

2. For use with a door latch unit including a latch bolt, a springurging said bolt to projected position, and opposed shoulder means forlimiting the extent of projection of said latch bolt, the combinationof: a strike adapted to be engaged by said latch bolt for retractingsaid bolt upon closing movement of such door, said strike being providedwith an opening adapted to receive said bolt therethrough when such dooris closed, a strike box in registration with said opening for receivingsaid bolt therein, a plate positioned in said box, means mounting saidplate below the level of said opening for limited adjustable movementtoward and away from said opening, and a stop or yieldable cushionmaterial carried by said plate and adapted to be engaged by said boltwhen the latter is projected to substantially its, full extent fornoiselessly absorbing the impact of said shoulder means, said meansincluding a spring in said box urging said plate toward said opening anda screw accessible through said opening and threadedly carried by saidbox for urging said plate against said spring.

3. For use with a door latch unit including a latch bolt, a springurging said bolt to projected position, and opposed shoulder means forlimiting the extent of projection of said latch bolt, the combinationof: a strike adapted to be engaged by said latch bolt for retractingsaid bolt upon closing movement of such door, said strike being providedwith an opening adapted to receive said bolt therethrough when such dooris closed, a strike box in registration with said opening for receivingsaid bolt therein, a plate positioned in said box, means mounting saidplate below the level of said opening for limited adjustable movementtoward and away from said opening, and a stop of yieldable cushionmaterial carried by said plate and adapted to be engaged by said boltwhen the latter is projected 'to "substantially its full extent fornoiselessly absorbing the impact'of said shoulder means, said meansincluding a headed screw accessible through said opening threadedlycarried by said box and provided with a head having'a slot for receivinga portion of said plate therein.

4. For use with a door latch unit including a latch bolt, a springurging said bolt to projected position, and opposed shoulder means forlimiting the extent of projection of said latch bolt, the combinationof: a strike adapted to be engaged by said latch bolt for retractingsaid bolt upon closing movement of such'door, said strike being providedwith an opening adapted to receive said bolt therethrough when such dooris closed, a strike box in registration with said "opening for receivingsaid bolt therein, a plate positioned in said box, means mounting saidplate below the level of said 'opening for limited adjustable movementtoward and away from said'opening, and a stop of yieldable cushionmaterial carried by said plate and adapted to be engaged by said boltwhen the latter is projected to substantially its full extent fornoiselessly absorbing the impact of said shoulder means, said platebeing swingably secured to said box for movement toward and away fromsaid opening, and said means comprising a spring in 'said "box forurging said plate toward said'opening and an adjustment screw threadedlycarried by said box and accessible through said opening for urging saidplate against said spring.

References cats in the file of this patent UNITED STATES PATENTS 412,986Schoen et al. Oct. 15, 1889 1,003,219 Voight Sept. 12, 1911 1,004,716Voight Oct. 3, 1911 1,005,841 Hurd Oct. 17, 1911 1,097,154 \Vright May19, l 9 l 4 1,903,782 Eyring Apr. 18, 1933 2,467,815 Curtiss Apr. 19,1949 FOREIGN PATENTS 28,066 Great Britain Nov. '19, 1898 445,803 GreatBritain Apr. 20, 1936

